Percussion extracting device



Filed oct. 28. 1941 \A MJ iii Patented Dec. 28, 1943 UNITED 'STATES PATENT GFFICE "l l-v 1 `2,337,971 PERCUSSION EXTRACTING DEVICE VOscarliuis` Caviglia, Buenos Aires, kArgentina npplieationoctober l28, 1941, serial No. 416,873

(G1. s2-4,0), v

51Claims.

' yThis invention'relates to a lpercussion yextractor device, .and `more particularly to a percussion lex- 1 tractor device foruse in dentistry'.

. `An object of the invention is to provide a unit jformed by a suitable combination of elements, 'which is easy to use,y safe tooperate in connec- 'tion with the extraction of bridges, bands, crowns and the Ilike indentistry, through the simple v`ac'- tuation of a-trigger.

The device which is the subjectwof the presen 1 invention is Aconstituted. mainly by. a hooking element or means removably :connected to a stem 'or guide and ending .in a head'having `a .larger f-section, where a hammer exerts the stress, said lhammer lbeing coaxially mounted Lon said stem and actuated by a spring, the assembly -being'-op yelated rand adjusted at will, so as to provide a rangerof percussionintensities. f n l Together with the main feature,` the device presents yother vfeatures, such as the inclusion of shock absorbing means, means for iixing the correct initial and operative positions, and others which will become apparent from the course of the present specification.

In order that the invention may be readily understood and carried into practice, the same has been illustrated by way of example in the accompanying drawing, wherein:

Figure 1 is an external view of the device;

Figure 2 is a longitudinal section of the same device in the final position or immediate to the stroke;

Figure 3 is a view similar to Figure 2, but showing the device during a phase of the charging operation;

Figure 4 is a view similar to Figure 3, but showing the device completely charged and ready for use;

Figure 5 is a plan view of Figure 1;

Figure 6 is a sectional view along the line a'b;

Figure '7 is a sectional view along the line c--d.

The same reference characters indicate like or corresponding parts or elements throughout the different iigures.

The device illustrated comprises a tubular supporting and guiding casing I, provided with a front cover 2 and a rear cover 3.

Cover 2 acts as a guide for the free linear play of a stem or shank-member 4 which extends out of said cover through an axial perforation therein. The free end of said shank 4 carries a hook member 5, ending in a curved end 6 and provided in the manner and for the purpose to be `de.-

scribped later.

'The shank 4 is inserted :in a hammer or-core member 9 in a manner so as to have freel linear play, 4the revolution `suriace oi saidv hammer 9 being provided throughout its extension witna plurality of notches defining v`annular toothed zones I, suitably equidistannvsaid vndtclfies being yengaged by a pawl II of` a trigger I2,` linked to a forked vsupport, vI?, integral with the casing I`.

.Said trigger rt2 is .opposed ,by `a laminar spring I4,

the pawl Il entering -into said casingl through an oriiice made therein.

The shank 4 is kept connected tothe toothed corey member .or hammer #by means ,of a member or rear head I5, against which said hammer strikes in its backward motion, said hammer exerting upon the shank the backward stress in the manner and for the purpose to be indicated hereunder.

The hammer 9 is actuated by an expansion spring I6, the last turn of which is located in a socket provided in the front head thereof, while the opposite end of said spring is secured to the front face of the cover 2.

The device also includes, on the inner portion of cover 3, an expansion spring I'I of the usual frusto-conical type, constituting the means for absorbing the shock of the head member I5 against the cover at the end of its backward stroke; it also includes on the front end of shank 4, a radial stop I8 operating in a slot I9, passing axially through the cover 2, including a plurality of complementary axial slots 20, said slots constituting the access means to the stop I8, so as to establish the blocking action of the rotary axial play of the shank 4 during the operation of hooking the device to the object to be ex-v tracted.

The reason for including this plurality of annular toothed zones I0 in the hammer member 9, is to enable the regulation of the traction force to be exerted by the hook 1 on the dental object to be extracted, which depends on the greater or lesser compression of the spring I6, and is subject to the engagement of the element I I with one of said toothed annular zones, it being understood that the more advanced the hammer is within ghe tubular element I, the greater the force will The operation of the device is as follows: The device is charged by pulling out the shank 4 which carries the hammer 9 the latter abutting against the paw] II, and causing the trigger I2 to move angularly on its support. 'Ihe advance of the shank 4 and hammer 9 is continued to the required degree, according to the necessary tension of spring I6 and the force required to extract the dental object, at which time the pawl II is inserted in one of the toothed zones I of the hammer,v for example the rear zone as shown in Figure 4 and which corresponds to the maximum force of the device, inasmuch as in this position the spring I6 is completely compressed.

Thereafter, the shank 4 is pushed in to the tubular element I, until the stop I8 remains out of the slot I9, at which time the shank is turned until the stop thereof entersany of the slots-2U,

into which the shank enters with the aid of the l tension of the shock-absorbing spring I1 operat- -ing on'the head member I5, the shank 4 being thus prevented from turning and therefore placing the device ready for use (Figure 4). The dental object to be extracted is hooked by the tooth 1 of hook 5, and at this moment the operator presses the trigger I 2, whereby the pawl I I releases the toothed hammer 9, the spring I6 then acting against said hammer, giving the same -tion is capable of being modified in construction Aand detail, Without departing from the scope Eof the invention as clearly set forth in the appended claims.

What I claim is:

1 A percussion extraction device, comprising a hooking element connected to a guiding stem and ending in a fixed head, said stem being coaxially provided with a hammer having notches and a spring, said elements being housed in a casing provided with a trigger actuating in said notches, so as to provide a charge for graduating the force of the element and the stroke of extraction by the discharge of said element.

2. A percussion extracting device as claimed in claim 1, Yincluding means for absorbing the percussion shock.

3. A percussion extracting device as claimed in claim 1, including means for guiding the hooking element and means for fixing the operative position thereof.

4. A percussion extracting device as claimed in claim 1, in which the hooking element is removably connected to the stem of the device.

5. A percussion extracting device comprising a substantially cylindrical casing, a cap at each end thereof, one of the caps having a central perforation, a tool stem located and guided in the perforation of the cap, an extraction tool being removably secured to the stem, said tool having a curved end provided with a tooth, the end of the stem within the casing having an enlarged head thereon, a hammer -slidable on the stem within the casing, annular notches provided along the length of the hammer, a spring around the stem and located between the perforated cap and hammer, a trigger pivoted to thecasing and cooperating With the notches in the hammer to hold the spring in compressed condition, and a spring in the casing above the enlarged head on the stem for absorbing the-shock of the blow delivered by the hammer to the head when the triggeris operated and transmitted along the stem. to the hook on the end of the tool for extractingV the object with which the hook may be engaged.,`

OSCAR LUIS CAVIGLIA.l 

